1. Introduction to Water Distribution System Analysis
CE 572 – Urban Water Systems Analysis
Larry A. Roesner, Ph.D., P.E.
Fall 2008

2. History of Water Distribution System Analysis
1936: Hardy Cross – steady state iterative algorithm solvable with slide rule
1960’s: Computerized Hardy Cross Models  Wood’s KYPIPE (early 1970’s)
Late 1970’s: Optimization algorithms (Alperovits and Shamir) and large system simulation capability (1,000s of pipes)
1990’s: Transient analysis on complex systems (water hammer)
1993: EPANet – Lew Rossman
1996: H20Net – MWH Soft, Inc (EPANet with GUIs and CAD interface)

3. Definitions water distribution system pipes, pumps, valves, and tanks
junction nodes
steady state
extended period simulation (EPS)
dynamic (unsteady) water quality modeling
transient analysis

4. Modeling Philosophy
System analysis to develop or improve a water distribution system taking into account:
Cost
Time
Safety
Ease of modification
Operation
Aid to communication
The dilemma: simplicity vs. accuracy

5. Model Development Formulation (conceptual analysis) Calibration
Verification, Validation, Confirmation
Refinement

6. Problems of Modeling Complexity of the real system
Calibration and data
Sensitivity
Numerical algorithms and methods
Adaptation of the model to the real system
Nesting of submodels

7. Model Formulation

8. Basic Terms in the Energy Equation

9. Solution of the Energy Equation

10. Problem

11. Solutions

12. H2ONET Solution

13. EPANET

14. RD 4 – EPANET Introduction
Access the EPANET Webpage and read the introductory material about the model
Download EPANET from the Web or access it from ENS “Engineering Applications”
Browse the EN2manual
Run the Tutorial
Due by Tuesday Sept 23rd